From nobody Fri Jun 24 14:35:21 2022 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 8DE7D87636E for ; Fri, 24 Jun 2022 14:35:21 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4LV05j2lLrz4nFr for ; Fri, 24 Jun 2022 14:35:21 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 3EB691176C for ; Fri, 24 Jun 2022 14:35:21 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 25OEZLh3003139 for ; Fri, 24 Jun 2022 14:35:21 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 25OEZLCO003138 for net@FreeBSD.org; Fri, 24 Jun 2022 14:35:21 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 264257] [tcp] Panic: Fatal trap 12: page fault while in kernel mode (if_io_tqg_4) - m_copydata ... at /usr/src/sys/kern/uipc_mbuf.c:659 Date: Fri, 24 Jun 2022 14:35:21 +0000 X-Bugzilla-Reason: CC AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 13.1-RELEASE X-Bugzilla-Keywords: crash, needs-qa X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: rscheff@freebsd.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@FreeBSD.org X-Bugzilla-Flags: maintainer-feedback? maintainer-feedback? maintainer-feedback- maintainer-feedback? mfc-stable13? X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1656081321; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=i9Afdm8+SOkUo73l970NqJ0309Mzij+/x9QJsZHZHZc=; b=bwSXOpfsbFhx/mrG2SeXaP00z2nVWDFSNqCGXivmZSrs3AmD3Eg7ldgVZPionUEKS6BmsU Y+sm137qaq6H4O3TF6qlzzIicb1q1Ra0ZIdxTTJDeuk86WymGAdqDFkuel+0Eh09stP7fe x1eH08bNWZ/PipZCXCktkbe+9TQu6N4cwXzmmzt1549aOwesfZHE/cQJ7KL3n3swdkhWKO dRG11qBGWlm4eZZZlIR62qRFl9JwvH2f/x+poZ3vh7nStEMbqTd21U92Kyz1ek2yIsDcfz ZJsaE9rTjQ3uPhgPUS2sYtIitJAzerzwQxiuItvwbQaPxNAlye1xHK0dwNbjBA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1656081321; a=rsa-sha256; cv=none; b=HGVmpJPHaDye3SUkd6QOrSPWogmcvdFous+RTG38/UCNoEMwGgPd52c38oNpsYBKCjrUq1 cjOzIVUt7sDlCDKjWHBtoX1SMPLFJnLHmSiGVVClRMGmGNjZqyjTDhh1vbl42YLUR9Ms0K 1pAA4SKbvydtoZef+s5Mc0DhiskAxNvKatZqPLliXXunD7rT/0DiG4GMHc6ofZTS4Zs07B HOo0r73TQzOtwxk+bQ6ztz18RjN540tUOQYDXmAd9IPSiJzPuEDgwpj+9uqZgFl9CVmFAa RiBhvUgRQ/9/xohuHNrLVO/jGMI5u9H8rHF1dEScfeaq4R98R40QDVvgrFoABg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D264257 --- Comment #74 from Richard Scheffenegger --- The offending TCP sessions we've seen so far all seem to be regular https sessions. For (yet unknown) reasons, rarely the FIN bit seems to get accoun= ted more than once - up to 6 times, from one of the logging patched kernels. With SACK rescue retransmissions, that can lead to having the sequence numb= er of one or more FIN bits included in the block which is to be retransmitted - and the panic happens, when the data byte at the sequence number of the FIN= bit is tried to be retranmitted... In your case, even though you didn't have SACK rescue retransmissions enabl= ed, the client of the offending session appears to have SACK'ed the 2nd retransmission of the (and empty) FIN packet with a "too high" sequence num= ber, in effect resulting in the same issue. This should be happening much less frequently than with the SACK rescue retransmissions. At the same time, it appears, that double-counting of FIN bits happens quite frequently, but is not easy to reproduce. Thus we are currently working on a patch which exposes this (in INVARIANTS kernels with panics, in production kernels by logging that unexpected state, and clearing it "on the fly"). See D35446 --=20 You are receiving this mail because: You are on the CC list for the bug. You are the assignee for the bug.=